Here's a place where I can post my thoughts on new papers, provide updates on my projects, and post info that will eventually be on my website The Theropod Database - http://theropoddatabase.com/ . It will center on theropods, but may delve into other topics as well such as phylogenetics.

Saturday, September 11, 2010

Do theropods described in Science and Nature get fully described later?

At the request of Mike Taylor, here's an update and expansion of a post I wrote for the DML last year. Basically, we have a system that rewards publishing in Nature and Science (the so-called tabloids) despite the fact papers in those journals are universally thought to be too short due to space restrictions. The usual response is that Nature/Science papers are just meant to be preliminary announcements that will be followed by more detailed coverage later. But how often does this actually happen?

Easy enough to find non-neornithine theropods thanks to The Theropod Database. Note I only included taxa which were first named in Nature and (new for this blog post) Science, not those (like Sinornithomimus) which were first announced in Nature but named elsewhere, nor those (like Protarchaeopteryx) which were first named in obscure journals then redescribed in Nature. I didn't count instances like Shuvuuia, where Chiappe (2002) did describe and illustrate more than was done in Nature, but only in the context of a chapter describing all alvarezsaurids. So while the skull was effectively redescribed (as it was the only complete alvarezsaurid skull known), comments on the postcrania are only mixed with descriptions of other taxa or generalized alvarezsaurid description. I also didn't include Majungatholus, which is a theropod described as a pachycephalosaur in Nature, which was later synonymized with Majungasaurus. Majungasaurus was redescribed in 2007 based mostly on new remains initially reported in 1998 in Science. So ... uh... I guess that taxon counts as a win for Science/Nature.

Eoraptor
Sereno, Forster, Rogers and Monetta, 1993. Primitive dinosaur skeleton from Argentina and the early evolution of Dinosauria. Nature. 361, 64-66.
Redescription in progress for over a decade for publication as a JVP monograph.

Baryonyx
Charig and Milner, 1986. Baryonyx, a remarkable new theropod dinosaur. Nature. 324, 359-361.
Charig and Milner, 1997. Baryonyx walkeri, a fish-eating dinosaur from the Wealden of Surrey. Bulletin of the Natural History Museum of London (Geology). 53, 11-70.

Giganotosaurus
Coria and Salgado, 1995. A new giant carnivorous dinosaur from the Cretaceous of Patagonia. Nature. 377, 224-226.
Not redescribed yet except for the braincase in 2002 (Coria and Currie).

Siamotyrannus
Buffetaut, Suteethorn and Tong, 1996. The earliest known tyrannosaur from the Lower Cretaceous of Thailand. Nature. 381(6584), 689-691.
Not redescribed.

Scipionyx
Dal Sasso and Signore, 1998. Exceptional soft tissue preservation in a theropod dinosaur from Italy. Nature. 392, 383-387.
Described in depth in Signore's thesis, which isn't published. Dal Sasso and Maganuco are writing a monograph which Auditore said would be out in 2009 or early 2010, but it seems to be delayed.

Gigantoraptor
Xu, Tan, Wang, Zhao and Tan, 2007. A gigantic bird-like dinosaur from the Late Cretaceous of China. Nature. 844-847.
Not redescribed.

Mei
Xu and Norell, 2004. A new troodontid dinosaur from China with avian-like sleeping posture. Nature. 431, 838-841.
Not redescribed.

Sinovenator
Xu, Norell, Wang, Makovicky and Wu, 2002. A basal troodontid from the Early Cretaceous of China. Nature. 415, 780-784.
Not redescribed.

Archaeornithoides
Elzanowski and Wellnhofer, 1992. A new link between theropods and birds from the Cretaceous of Mongolia. Nature. 359, 821-823.
Elzanowski and Wellnhofer, 1993. Skull of Archaeornithoides from the Upper Cretaceous of Mongolia. American Journal of Science. 293-A, 235-252.

Unenlagia
Novas and Puerta, 1997. New evidence concerning avian origins from the Late Cretaceous of Patagonia. Nature. 387: 390-392.
Not redescribed except the ilium by Novas (2004).

Sinornithosaurus
Xu, Wang and Wu, 1999. A dromaeosaurid dinosaur with filamentous integument from the Yixian Formation of China. Nature. 401, 262-266.
Not redescribed except for the skull (Xu and Wu, 2001) and the pes (Xu and Wang, 2000).

Microraptor
Xu, Zhou and Wang, 2000. The smallest known non-avian theropod dinosaur. Nature, 408, 705-708.
The holotype has not been redescribed, though two other specimens were monographed (Hwang et al., 2002).

Apsaravis
Norell and Clarke, 2001. Fossil that fills a critical gap in avian evolution. Nature. 409, 181-184.
Clarke and Norell, 2002. The morphology and phylogenetic position of Apsaravis ukhaana from the Late Cretaceous of Mongolia. American Museum Novitates. 3387, 1-46.

So that's Nature, but what about Science?

Cryolophosaurus
Hammer and Hickerson, 1994. A crested theropod dinosaur from Antarctica. Science. 264:828-830.
Smith, Makovicky, Hammer and Currie, 2007. Osteology of Cryolophosaurus ellioti (Dinosauria: Theropoda) from the Early Jurassic of Antarctica and implications for early theropod evolution. Zoological Journal of the Linnean Society. 151, 377-421.

So, of all 33 theropods described in Nature, 25 (76%) have yet to be fully described in a published work. Of all 11 theropods described in Science, 8 (73%) have yet to be fully described. So in total, 75% haven't been redescribed.

To be a bit more fair, of the 25 taxa described at least a decade ago, 17 (68%) have yet to be fully described. Hmm... doesn't really change the ratio.

9 comments:

"I didn't count instances like Shuvuuia, where Chiappe (2002) did describe and illustrate more than was done in Nature, but only in the context of a chapter describing all alvarezsaurids. So while the skull was effectively redescribed (as it was the only complete alvarezsaurid skull known), comments on the postcrania are only mixed with descriptions of other taxa or generalized alvarezsaurid description."

Add in the descriptions & figures by Sereno (2001*), including details of the orbital, dental, and pectoral regions, and it seems that most of the basic anatomical work on the available Shuvuuia cranial material has been attempted. Furthermore, Suzuki et al (1998#), supplemented the known cranial information with a paper on additional postcrania of Shuvuuia.

I think Shuvuuia SHOULD be counted as case where the taxon was satisfactorily more fully described at a later date.

#Suzuki, S., L. M. Chiappe, G. J. Dyke, M. Watabe, R. Barsbold, and K. Tsogtbaatar. 2002. A new specimen of Shuvuuia deserti Chiappe et al., 1998, from the Mongolian Late Cretaceous with a discussion of the relationships of alvarezsaurids to other theropod dinosaurs. Natural History Museum of Los Angeles County, Contributions in Science 494:1-18.

"GiganotosaurusCoria and Salgado, 1995. A new giant carnivorous dinosaur from the Cretaceous of Patagonia. Nature. 377, 224-226.Not redescribed yet except for the braincase in 2002 (Coria and Currie)."

I agree very much that the known specimens overall remain unsubscribed; the dentary and additional cranial info have seen the light of publication:

For Shuvuuia, the line drawings and photographs by Sereno hardly count as a redescription. Any more than Calvo's (1999) photo of Giganotosaurus' pectoral girdle means it has been properly described. Suzuki et al.'s "Shuvuuia" specimen is another taxon (Longrich and Currie, 2009). The skull has been described in Dufeau's (2003) thesis, but this remains unpublished (and I don't have a copy). Since there's nowhere you can go to read a description of the axial skeleton, pectoral girdle, forelimb, pelvis or hindlimb, I can hardly call Shuvuuia satisfactorily more fully described.

I was unaware of the Giganotosaurus endocast paper. I find it a sad state of affairs that Mapusaurus was properly described before Giganotosaurus.

MasiakasaurusHolotype has been redescribed in JVP, and new materials (undescribed thus far) are also known.

ps.

The scanty holotype of Enantiornis was redescribed and figured in: Chiappe, L. M. 1996. Early avian evolution in the southern hemisphere: the fossil record of birds in the Mesozoic of Gondwana. Memoirs of the Queensland Museum 39:533-554.

Similarly, the original material that Nanantius is based on is meagre, and was discussed in Chiappe above, and in Kurochkin & Molnar, 1997. There isn't (comparatively) much more information to be gained from having a redescriptive paper on the Nanantius holotype compared to most of the theropods on this list, which are based on more complete remains, and therefore require time and publication space to detail them. That Archaeornithoides was described a year after being named, compared with Baryonyx (11 years) tells you something about the differences between the tasks at hand (of detailing these very different specimens).

Thanks for the ones I missed. I haven't yet added Tawa to my site, and I had somehow not listed Masiakasaurus' original description.

Enantiornis' description in Chiappe (1996) is about as short as a tabloid description (less than half a page), and Chiappe claims a more detailed description would appear "elsewhere (Chiappe and Walker in preperation)." That refers to the 2002 Mesozoic Birds volume I assume, but while that remains the best source for illustrations of Enantiornis, there was no separate description of the taxon there.

I agree Nanantius is more fragmentary than the others, but since so few enantiornithines were known at the time, a redescription could be quite informative. Much like someone needs to redescribe Alexornis...

I certainly understand specimens can take a long time to properly describe, but it often seems workers throw out a preliminary paper, then go on to preliminarily describe the next thing instead of finish the job.

Hello, i have a question to you, do you think it could be possible that deltadromeus and bahariasaurus whjere just closley releated like cougar and jaguarundi, wolf and coyote rather than the same species ??